REMarkerClusterer creates and manages per-zoom-level clusters for large amounts of markers.

As seen in Pinsnap iPhone app. REMarkerClusterer was inspired by the Apple Photos app on the iPhone, REMarkerClusterer mimics it's behaviour providing animations for grouping and ungrouping clusters.

How it works

The REMarkerClusterer will group markers into clusters according to their distance from a cluster's center. When a marker is added, the marker cluster will find a position in all the clusters, and if it fails to find one, it will create a new cluster with the marker. The number of markers in a cluster will be displayed on the cluster marker. When the map viewport changes, REMarkerClusterer will destroy the clusters in the viewport and regroup them into new clusters.

Requirements

• Xcode 4.6 or higher
• Apple LLVM compiler
• iOS 5.0 or higher
• ARC (if you want to use in a project without ARC just add the flag -fobjc-arc to the files in the Build Phases tab of your project)

Demo

Build and run the REMarkerClustererExample project in Xcode to see REMarkerClusterer in action.

Installation

Manual Install

REMarkerClusterer requires the MapKit and CoreLocation frameworks, so the first thing you'll need to do is include the frameworks into your project.

Now that the framework has been linked, all you need to do is drop files from REMarkerClusterer folder into your project, and add #include "REMarkerClusterer.h" to the top of classes that will use it.

Example Usage

// Add map view
//
self.mapView = [[MKMapView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
self.mapView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
[self.mapView setRegion:MKCoordinateRegionMake(CLLocationCoordinate2DMake(37.786996, -97.440100), MKCoordinateSpanMake(30.03863, 30.03863)) animated:YES];
[self.view addSubview:self.mapView];

// Create clusterer, assign a map view and delegate (MKMapViewDelegate)
//
self.clusterer = [[REMarkerClusterer alloc] initWithMapView:self.mapView delegate:self];

// Set smaller grid size for an iPad
//
self.clusterer.gridSize = UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone ? 25 : 20;
self.clusterer.clusterTitle = @"%i items";

// Populate with sample data
//
NSDictionary *data = [NSDictionary dictionaryWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"Points" ofType:@"plist"]];

[data[@"Points"] enumerateObjectsUsingBlock:^(NSDictionary *dictionary, NSUInteger idx, BOOL *stop) {
    REMarker *marker = [[REMarker alloc] init];
    marker.markerId = [dictionary[@"id"] integerValue];
    marker.coordinate = CLLocationCoordinate2DMake([dictionary[@"latitude"] floatValue], [dictionary[@"longitude"] floatValue]);
    marker.title = [NSString stringWithFormat:@"One item <id: %i>", idx];
    marker.userInfo = @{ @"index": @(idx) };
    [self.clusterer addMarker:marker];
}];

// Create clusters (without animations on view load)
//
[self.clusterer clusterize:NO];

// Zoom to show all clusters/markers on the map
//
[self.clusterer zoomToAnnotationsBounds:self.clusterer.markers];

Contributors

Nicolas Yuste (@nicoyuste) Thomas Kollbach (@toto) Markus Emrich (@jaydee3)

Contact

Roman Efimov

• http://github.com/romaonthego
• http://twitter.com/romaonthego
• [email protected]

Credits

Partially based on MarkerClusterer Javascript library by Xiaoxi Wu (http://gmaps-utility-library-dev.googlecode.com)

License

REMarkerClusterer is available under the MIT license.

Copyright © 2011-2013 Roman Efimov.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.